New loading standard
The Department will shortly release for public consultation a proposal to reference the new joint Australian/New Zealand Standard AS/NZS 1170 Structural Design Actions in the Verification Method B1/VM1.
The proposed reference will replace the existing loading Standard NZS 4203. It will contain a number of further amendments to AS/NZS 1170 to make the new Standard suitable for use in the Verification Method. It is also proposed to remove the citation of some older Standards.
The proposed referencing of the new Standard AS/NZS 1170 recognises emerging information on hazards, particularly about wind and earthquakes.
In the 12 years since NZS 4203 was cited, knowledge of the hazard environment has developed greatly. For example, there are many areas in New Zealand where the most recent seismic data indicates that higher loads should be used in building design.
There is also better understanding of the wind environment and the hazards it presents, which is reflected in the new Standard. The new Standard also:
- increases some building design live loads
- increases traffic-barrier impact-design requirements
- simplifies wind zones in New Zealand, reducing them from seven to three
- revises specifications for snow and wind loads
- assigns higher seismic design loads for buildings of higher importance, such as hospitals and other buildings, that are expected to continue functioning after an earthquake.
The proposals include a requirement for chartered professional engineers to sign off designs based on the Standard. This measure would recognise the skills and experience that only professional engineers can bring to the building process. It is consistent with the principles behind the licensed building practitioner scheme.
The Department considers that buildings designed to the new Standard will better reflect New Zealand conditions.
The proposal is the next phase of an ongoing process for the revision of structural design requirements.
Later phases will deal with design standards for concrete, steel, masonry and other materials.
The Department is seeking public comment on the proposal to reference AS/NZS 1170 in the Verification Method for Building Code Clause B1 Structure. Comments are invited from the general public, including engineers, designers, industry organisations and building users. Details of the proposal will be available on the Department's website (www.dbh.govt.nz).